Structure and protein kinase C stimulating activities of lactam analogues of human parathyroid hormone fragment
| Autor: | Witold Neugebauer, James F. Whitfield, Gordon E. Willick, Lyne Gagnon |
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| Rok vydání: | 2009 |
| Předmět: |
Circular dichroism
Lactams Stereochemistry Molecular Sequence Data Parathyroid hormone Peptides Cyclic Biochemistry Protein Structure Secondary Structure-Activity Relationship chemistry.chemical_compound Protein structure Tumor Cells Cultured Animals Humans Structure–activity relationship Amino Acid Sequence Protein Kinase C Protein kinase C chemistry.chemical_classification Chromatography Osteosarcoma Parathyroid hormone receptor Circular Dichroism Peptide Fragments Stimulation Chemical Rats Enzyme chemistry Parathyroid Hormone Lactam Spectrophotometry Ultraviolet |
| Zdroj: | International Journal of Peptide and Protein Research. 43:555-562 |
| ISSN: | 0367-8377 |
| Popis: | Five analogues of human parathyroid hormone (hPTH-(20-34)-NH2, I; cyclo[Lys26-Asp30]-hPTH-(20-34)-NH2, II; cyclo[Glu22-Lys26]-hPTH-(20-34)-NH2, III; cyclo[Lys27-Asp30]- hPTH-(20-34)-NH2, IV; and [Leu27]-hPTH-(20-34)-NH2 V) were tested for their ability to promote membrane-bound protein kinase C (PKC) activity in a rat osteosarcoma cell line (ROS 17/2). Analogues I, II and V stimulated PKC activity in the picomolar range, whereas analogues III and IV did not stimulate this activity at any concentration tested. The circular dichroism spectra in neutral, aqueous buffer showed an increase in alpha-helix in analogues II, III and V as compared to I; this increase appeared to be in the region of the cyclic lactam structure. Analogue IV did not adopt a helical structure, even in the presence of 40% trifluoroethanol, a helix-promoting solvent. The remaining analogues showed a three- to four-fold enhancement of alpha-helix in this solvent. Analogues II and III had increased retention times in reversed-phase chromatography, as compared to I and IV. This is consistent with a stabilization of amphiphilic helix in analogues II and III compared with I and IV. The data suggest that in the region bounded approximately by residues 24-32, an amphiphilic alpha-helix is important for correct functional binding to the PTH receptor. |
| Databáze: | OpenAIRE |
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